Reporters surrounds the 2013 Fusion Energi at the North American International Auto Show at Cobo Center in Detroit. / Romain Blanquart, Detroit Free Press

by Chris Woodyard, USA TODAY

by Chris Woodyard, USA TODAY

For car buyers who dreamed of getting 100 miles a gallon, Ford has your car.

The automaker is announcing today that the plug-in hybrid version of the 2013 Ford Fusion will be certified by the Environmental Protection Agency as getting the electric equivalent of 108 miles a gallon in city driving, 92 MPGe in highway driving for a combined 100 MPGe overall.

The plug-in Fusion's chief rival, the Toyota Prius plug-in, gets 95 MPGe. Still waiting in the wings is the plug-in version of Honda's Accord, which hasn't been rated yet.

The government calculation is based on the idea that people will plug in their cars then drive them on electric power only until the juice runs out and the gas motor takes over. So the actual mileage that anyone gets depends on their daily commute. The shorter the commute, the more miles driven on electric power, the higher the the gas mileage.

The plug-in version is the latest version of the new 2013 Fusion, the car that wowed the North American International Auto Show in January and has generally received good reviews in its various incarnations. There's the regular ol' gas model, two turbocharged EcoBoost versions, a hybrid and now the plug-in hybrid.

The plug-in version of the Fusion, called the Fusion Energi, is the last one to come to showrooms at a base price of $39,495 plus delivery charges, almost identical to the Prius plug-in. Ford says additional pricing details will be announced closer to launch.

The price is almost twice the $21,700 that someone would pay for the absolute rock-bottom cheapest conventional Fusion, but Ford says the gasoline savings will add up. It says the plug-in could save $6,850 in gas costs over a typical five years of driving.

"The Fusion Energi plug-in hybrid is the exclamation point for Ford's transformed lineup of fuel-efficiency leaders that now beats Toyota across the board," said Raj Nair, a Ford group vice president, in a statement.

The Fusion line was recently named Green Car of the Year at the Los Angeles Auto Show. Green Car Journal's Ron Cogan, who runs the competition, says Ford showed how it can bring gas savings and ecology to a mass-market car with the Fusion's various versions.